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Abstract:

The invention relates to a device for inductively transmitting electrical
energy to displaceable consumers (F1-F13) that can be moved along a
track, having a primary conductor arrangement (2) divided into route
segments (3-7) that are electrically separated from each other, and
extending along the track, wherein individual route segments (3-7) are
each associated with at least one current source (3'-7') for imprinting a
continuous current into each of the route segments (3-7), and to a
corresponding method. The aim of the invention is to supply the
displaceable consumers in an energy-saving manner with electric energy
matched to demand, and to allow short reaction times when operating the
device. This aim is achieved by providing the device with a means (11)
for determining the total power of the displaceable consumers (F1-F13)
present in each of the individual route segments (3-7) and with a means
(11) for actuating the current sources (3'-7') for applying the
electrical continuous current corresponding to the total power required
for each route segment (3-7), or by determining, according to the method,
the required total power of the displaceable consumers (F1-F13) present
in each route segment and applying an electrical continuous current to
each route segment (3-7) by means of the associated current source
(3'-7'), said current corresponding to the total power required therein.

Claims:

1-12. (canceled)

13. Device for inductive transmission of electrical energy to moving
consumers which can be made to travel along a route with a primary
conductor arrangement running along the route and divided into route
sections which are separated from one another electrically, wherein the
individual route sections are each assigned at least one current source
for impressing a constant current in the respective route sections,
wherein a means is provided for determining the total power required in
each case in the individual route sections by the moving consumers
located there and a means for actuating the current sources for
impressing the constant electrical current corresponding to the required
total power of the respective route section.

14. Device according to claim 13, wherein the means for determining the
required total power comprises an assignment table in which different
supply levels of the required total power in a route section are assigned
values of the constant current to be impressed in the route section, the
values for the constant current in each case corresponding to the
greatest required total power in this supply level.

15. Device according to claim 13, wherein power values assigned to the
different operating states of the consumers are stored in the means for
determining the required total power.

16. Device according to claim 15, wherein the consumers exhibit a vehicle
control, a propulsion drive and one or more working units, the power
values required for their operation being stored in the means for
determining the required total power.

17. Device according to claim 13, wherein the route sections are assigned
current measuring devices for determining the constant current currently
being provided for the respective route section.

18. Method for inductive transmission of electrical energy to moving
consumers which can be made to travel along a route and which are
supplied inductively with electrical energy from a primary conductor
arrangement running along the route and divided into route sections which
are separated from one another electrically, wherein a constant current
is impressed on the individual route sections in each case from at least
one current source assigned to the respective route section, wherein the
total power required by the moving consumers located there is determined
for each route section and a constant electrical current corresponding to
the total power required there is impressed on the respective route
section by the associated current source.

19. Method according to claim 18, wherein different total powers in a
route section are assigned to different supply levels, wherein a supply
level is selected according to the determined required total power in a
route section and a value for the constant current to be impressed
assigned to the selected supply level in the route section is impressed
on the route section.

20. Method according to claim 19, wherein the values for the constant
current to be impressed assigned to the individual supply levels in the
route section in each case correspond to the maximum total power in this
supply level.

21. Method according to claim 18, wherein different operating states of
the consumers in a route section are determined, and the required total
power in this route section is determined according to the determined
operating states.

22. Method according to claim 21, wherein the operating states comprise a
control state of the consumer with a first power value, a propulsion
state of the consumer with a second power value and/or a working state of
the consumer with a third power value.

23. Method according to claim 21, wherein a future required total power
of one of the route sections is determined from a given future operating
state of the consumers currently located there.

24. Method according to claim 21, wherein a future required total power
of one of the route sections is determined from a given future operating
state of the consumers located in at least one adjoining route section.

Description:

[0001] The invention relates to a device for inductive transmission of
electrical energy to moving consumers according to the preamble of claim
1 and to a method for this according to the preamble of claim 6.

[0002] When electrical energy is transmitted to moving consumers,
particularly in systems with consumers guided along a predetermined route
such as telpher systems or driverless transport systems in assembly
plants or warehouses with shelving, it is known for the complete route to
be divided at least electrically into individual route sections. As a
rule, the individual route sections are each supplied with electrical
energy through their own supply modules. To increase the safety of
unoccupied route sections and reduce the power requirement of known
systems, usually only those route sections on which moving consumers are
in operation are supplied with electrical energy.

[0003] Thus, DE 602 90 141 T2 discloses an automatic transport and
personal guidance system and the control of transport modules in such a
system with a track as guide device for the transport modules. In
addition, this system comprises an electrical supply system with a
distribution device for electrical supply for different successive supply
circuits. The supply system controls the movement of the transport
modules by making different supply circuits electrically live or dead.
Here, when a transport module is present in a supply circuit, this
prevents one or more circuits arranged directly behind the circuit being
used from being made live in order to maintain a safety gap between the
different transport modules travelling separately from one another on the
track. This ensures automatic movement of the vehicles when the transport
modules are supplied with electrical energy through the supply circuits.
If the transport modules are not supplied with electrical energy by the
supply circuits, a braking device is automatically tripped in the
transport modules in these supply circuits.

[0004] DE 601 25 579 T2 discloses a contactless current supply device in
which a primary induction line uses high-frequency current to transmit
electrical energy without contact to a secondary load, the secondary load
being a moving car which is assigned to a robot area. In order to be able
to repair or service electrical equipment in the moving car, the
corresponding section of the movement track can be switched off so that
the car is not supplied with electrical voltage.

[0005] WO 93/23909 also describes a roadway for inductively supplying an
automatic guided vehicle with a route which is divided into individual
segments and is only supplied with energy when a vehicle is in this
segment.

[0006] WO 2007/006400 A2 discloses a primary conductor divided in multiple
sections which are not separated electrically from one another, whereby
respective route controllers can be assigned to each section allowing
each route section to be feed forward controlled, feed back controlled or
both together. The different route sections do not contain respective
current sources for impressing a constant current, but there is only one
single supply circuit for supplying alternating current to the primary
conductor, whereby the route controllers are enabled for data
transmission with the supply circuit. The route controllers can transmit
the number of consumers to be supplied in the respective route section
and further information, for example the power required by the consumers
and the capacity of energy contained in their energy buffers, to the
supply circuit. On that basis the supply circuit is enabled to calculate
the required power and the pulse with modulation ratio and/or the
characteristic of the amplitude value of the current of the complete
primary conductor and to impress this value correspondingly. Further,
sinusoidal current blocks are impressed during an on-period. During an
off-period the current in the primary conductor is switched off, whereby
during that time period an energy buffer of the consumer supplies the
necessary voltage. A power supply to different route sections based on
the required power thereof is not possible.

[0007] DE 10 2007 026 896 A1 discloses a method for power-adaptive control
of a generated transmission conductor current, which is impressed in a
transmission route of an arrangement for inductive transmission of
electrical power to at least two movable consumers. A transmission
conductor shown therein is not divided into route sections with
respective assigned current source for impressing a constant current into
each respective section. Hence a power supply of different route sections
dependent on the required power is not possible.

[0008] In installations in which a plurality of moving consumers travel
over the different route sections at different times there is a desire to
reduce the power requirement in a simple manner. Often the moving
consumers carry out additional activities, for example turning, lifting
or swivelling operations to raise loads or grip components. This results
in a wide variety of requirements of the power required at the consumers.
For example, a travelling consumer or vehicle only requires electrical
power for its car control and its propulsion drive, whereas more
electrical power is required for an additional turning movement. However,
often such vehicles are also stationary in a waiting (standby) position,
i.e. in this case it is only necessary to supply the car control with
electrical power. Even when there are only stationary vehicles with a
relatively low power requirement in a route section, in the known
installations the maximum power requirement is maintained and a route
section is only switched to a state in which it is free of current and
voltage in the complete absence of vehicles. As installations of this
kind are often operated with a constant current supply, the result is a
constant high current in the current and voltage-carrying supply elements
of the route sections, leading to continuous high power losses.

[0009] In the known installations if the power supply were also switched
off in route sections in which all the vehicles are in a waiting
(standby) position, the car controls of the vehicles in this route
section would initially have to be started up when this route section is
restarted, preventing rapid or immediate restarting of the vehicles. To
avoid this, the vehicles could be equipped with a vehicle battery which
guarantees the power required to maintain the operation of the car
control even when the route section is switched off. However, if a
vehicle is stationary for an extended period, the vehicle battery is
discharged so that restarting is only possible with the time consuming
start-up of the car control. To guarantee operation with optimum
reliability and speed, it is then necessary either to provide a battery
with a greater capacity or to supply the route section continuously with
the full electric power as known.

[0010] Therefore, the underlying object of the present invention is to
provide a device and a method for inductive transmission of electrical
energy to moving consumers, which overcome the above-named disadvantages
and allow an energy-saving supply of electrical energy to the moving
consumers matching demand and short reaction times in the operation of
the device.

[0011] The invention achieves this object with a device for inductive
transmission of electrical energy to moving consumers with the features
of claim 1 and with a method for this with the features of claim 6.
Advantageous embodiments and expedient developments of the invention are
disclosed in the subordinate claims.

[0012] According to the invention, a device named at the start for
inductive transmission of electrical energy to moving consumers is
characterised in that a means is provided for determining the total power
required in each case in the individual route sections by the moving
consumers located there and a means for actuating the current sources for
impressing the constant electrical current corresponding to the required
total power of the respective route section. According to the invention,
a method named at the start for inductive transmission of electrical
energy to moving consumers is characterized in that the total power
required by the moving consumers located there is determined for each
route section and a constant electrical current corresponding to the
total power required there is impressed on the respective route section
by the associated current source. This makes it possible to obtain a
substantial reduction in the energy required by the device without any
major effect on the operation of the device, as only the required power
is provided in each case in the individual route sections, and so the
power loss can be reduced.

[0013] In one advantageous embodiment of the invention, the means for
determining the required total power can comprise an assignment table in
which different supply levels of the required total power in a route
section are assigned values of the constant current to be impressed in
the route section. Advantageously, the values for the constant current
can correspond to the greatest required total power in this supply level.
In one advantageous variant of the method according to the invention, a
supply level can be selected according to the determined required total
power in a route section and a value for the constant current to be
impressed assigned to the selected supply level in the route section can
be impressed on the route section. This makes it possible to avoid
continuous adjustment of the impressed constant current to minor
fluctuations in the required total power.

[0014] In a further advantageous variant, power values assigned to
different operating states of the consumers can be stored in the means
for determining the required total power. In an advantageous development
of this variant, the consumers can exhibit a control, a propulsion drive
and one or more working units, the power values required for their
operation being stored in the means for determining the required total
power.

[0015] To determine the constant current currently being impressed in a
route section, current measuring devices can be provided in the route
sections.

[0016] In a further advantageous variant of the invention, different
operating states of the consumers in a route section can be determined
and the required total power in this route section can be determined
according to the determined operating states. This allows different
operating states of the consumers to be linked directly with the total
power required by the current sources in the individual route sections on
the basis of the previously known power values required there. In one
advantageous development of this variant, the operating states can
comprise a control state of the consumer with a first power value, a
propulsion state of the consumer with a second power value and/or a
working state of the consumer with a third power value.

[0017] In one advantageous embodiment of the invention, the required total
power of at least one of the route sections can be determined from the
current operating state of one or more of the consumers.

[0018] In one advantageous development, a future required total power of
one of the route sections can he determined from a given future operating
state of the consumers currently located there. This can be used
advantageously when the device is operated controlled, and the means for
determining the total power required in each of the individual route
sections by the moving consumers located there and the means for
actuating the current sources can take account of operating states
already known in advance and required total power levels, i.e. from
knowledge of the future operating situation, when controlling the device.

[0019] In a further preferred embodiment, a future required total power of
one of the route sections can be determined from a given future operating
state of the consumers located in at least one adjoining route section.
This makes it possible to take early account of consumers shortly
travelling into a route section when determining the required total
power, in particular for future times, so that any switching operations
for the constant current fed in can be avoided. This makes it possible to
avoid switching losses in the current sources and reduce their load.

[0020] Further particular features and advantages of the invention will
become apparent from the following description of a preferred embodiment
example with reference to the drawings in which:

[0021] FIG. 1 shows a diagrammatic view of a device according to the
invention with a plurality of moving consumers in a first operating
state,

[0022] FIG. 2 shows the diagrammatic illustration in FIG. 1 with the
moving consumers in a second operating state,

[0023] FIG. 3 shows a diagrammatic illustration of a part of a device
according to the invention,

[0024]FIG. 4 shows a flow diagram for the operation of the device
according to the invention.

[0025] FIG. 1 shows a device according to the invention for inductive
transmission of electrical energy to moving consumers F1 to F13 in the
form of a telpher system 1 known per se with a primary conductor
arrangement 2 known per se which runs along a route not shown in the
drawing.

[0026] The primary conductor arrangement 2 is divided into a total of five
electrically separated route sections, a first and second collecting
section 3 and 4 respectively, an outward journey section 5, a working
section 6 and a return journey section 7. The first and second collecting
sections 3 and 4 respectively can be connected mechanically at one end
with the outward journey section 7 by means of a set of points 8 and at
their other end with the return journey section 7 by means of a set of
points 9, without any electrical coupling taking place.

[0027] The individual route sections 3 to 7 arc in each case supplied by
their own current sources 3' to 7' which impress a constant electric
current of different intensity in the route sections 3 to 7 according to
need. As the transmission of energy to the consumers F1 to F13 is carried
out inductively, the constant current is an alternating current which
produces an alternating magnetic field. The current sources 3' to 7' can
be produced in a manner known per se and for their part are connected to
a three-phase 50 Hz/400 V electrical energy supply network 10. The
current sources 3' to 7' are also connected with an installation control
11 which monitors the entire operation of the device 1 and in particular
controls the current sources 3' to 7'.

[0028] The installation control 11 represents a means for determining the
total power required in each case in the individual route sections 3 to 7
by the moving consumers F1-F13 located there and a means 11 for actuating
the current sources 3' to 7' to impress the constant electric current
corresponding to the required total power of the respective route section
3 to 7 and for its part can be connected with a higher level plant
control not shown in the drawing. The installation control 11 can be
constructed in the conventional way centrally on one computer or
decentrally on distributed computers. In the present case, the
installation control 11 can actuate the current sources so that they
supply a constant current of the maximum current intensity IVL at
full load and current intensities of a third or half the maximum current
intensity IVL at lower loads.

[0029] The telpher system 1 also exhibits a plurality of moving consumers
in the form of cars F1 to F13 operated by electric motor, as used for
example in the manufacture of motor vehicles. The inductive supply of
electrical energy to the cars F1 to F13 is provided in a manner known per
se by means of the primary conductor arrangement 2 running along the
route and secondary pickup devices arranged on the cars F1 to F13. The
cars F1 to F13 in each case exhibit an electrical propulsion drive, a car
control and electrically operated working units, e.g. gripping, lifting
or turning devices for vehicle body parts to be worked on by further
working installations in the working section 6.

[0030] The power values for different operating states for a car F1 to F13
are in the present case approx. 200 W for the car control, approx. 1000 W
for the propulsion drive and approx. 2000 W for the working and turning
movement of the working unit. Thus, a resting car F1 to F13 only requires
200 W for the car control, a travelling car approx. 1200 W for car
control and propulsion drive, a stationary working car approx. 2200 W for
car control and working unit and a travelling working car approx. 3200 W.
Depending on need, the individual operating states can occur
simultaneously, and then the power required by the individual car is
determined by adding together the different power values for the
individual operating states.

[0031] In FIG. 1 a car F1 is already in the first collecting section 3 and
travelling to a waiting (standby) position shown in FIG. 2. During its
travel, the propulsion drive of the car F1 and its car control are in
operation and these are supplied with electrical energy from the current
source 3'. Further cars F7 to F10 in the first collecting section 3 are
in a waiting (standby) position so that only their car control is in
operation. In FIGS. 1 and 2 the operation of the propulsion drive of a
car F1 to F13 is marked by a straight arrow "" and the operation of
the car control by a circle "∘". To supply the cars F1 and F7
to F10, the first collecting section 3 is supplied with only half the
maximum constant current IVL by the associated first current source
3'.

[0032] The second collecting section 4 in FIG. 1 only contains three
"resting" vehicles F11 to F13, and therefore only requires a third of the
maximum constant current IVL to supply their car controls with
electrical power from the current source 4'. Thus, the total power
required there is three times the amount of power required to operate a
car control.

[0033] Vehicles F5 and F6 in FIG. 1 are on the outward journey section 5
and moving to the working section 6. As the two vehicles F5 and F6 only
require the power required for the propulsion drive and car control, it
is sufficient to supply the outward journey section 5 with only half the
maximum constant current IVL from the current source 5'.

[0034] Cars F2, F3 and F4 in FIG. 1 are in the working section 6, in which
car F2 is moving forwards with its propulsion drive and car control in
operation, car F3 is moving forwards and carrying out a turning movement
indicated by a rotating arrow "" with one working unit, while car F4 is
stationary and its working unit is carrying out a turning movement. The
turning movement of the working units of cars F3 and F4 requires
additional power compared to the simple propulsion drive of car F2. The
working section 6 is consequently supplied with the maximum constant
current IVL by the current source 6'.

[0035] In contrast, the completely empty return journey section 7 can be
switched to a completely currentless and voltageless state, so the
current source 7' does not supply current to the return journey section.

[0036] In FIG. 2 the car F1 is also in a waiting (standby) position, so
there is no longer any need to supply any power for its propulsion drive.
The current source 3' of the first collecting section 3 can then be
reduced from half to a third of the maximum constant current IVL.
This saves additional power as the losses from the constant current in
this collecting section 3 can be reduced again. The state in the second
collecting section 4 remains unchanged.

[0037] As the cars F2 to F4 in FIG. 2 have travelled out of the working
section 6 and moved into the return journey section 7, but the working
units are no longer carrying out any turning movement, the return journey
section 7 is only supplied with half the maximum constant current
IVL by the current source 7' to supply the propulsion drives and car
controls of the cars F2 to F4. In contrast, in FIG. 2 the cars F5 and F6,
which have travelled out of the outward journey section 5, are in the
working section 6 where their working units arc now both carrying out a
turning movement so that there the required total power is the maximum
and as before the maximum constant current IVL must be provided. In
contrast, the outward journey section 5 is now free of cars so that it no
longer has to be supplied with power from the current source 5' and thus
can be switched to a currentless and voltageless state by the
installation control 11.

[0038] FIG. 3 shows diagrammatically a part of the electrical system of
the embodiment according to FIGS. 1 and 2. The three route sections 5, 6
and 7 are shown here by way of example, but the design of the other route
sections 3 and 4 is the same. As the route sections 3 to 7 are of
identical design, the route section of the outward journey section 5 in
which a single car F5 is located in FIG. 3, is described in the following
by way of example.

[0039] The outward journey section 5 exhibits as primary conductor
arrangement 2 an outward line 5h known per se and a return line 5r. The
secondary pickup device of the car F5 which is not shown in FIG. 3 is
guided along the outward line 5h so that electrical energy is transmitted
to the car F5 inductively. The electrical energy for the outward line 5h
is provided by a power module 5a of the current source 5'. The power
module 5a is embodied in a manner known per se as an inverter which is
supplied from the voltage system 10. The power module 5a is actuated by a
power control 5b which as input signals receives both the operating
parameters of the power module 5a, the current in the outward journey
section 5 measured at the return line 5r by means of a current measuring
device 5c known per se, and control signals from the installation control
11.

[0040] The installation control 11 transmits start, stop and other
operating signals for the cars F1 to F13 to the power control 5b, i.e. in
the present embodiment example determines all the functions for the
operation of the cars F1 to F13. This also includes signals for the route
sections to be travelled, the places and times at which loads are to be
lifted, set down or turned etc. In an alternative embodiment, the cars F1
to F13 can also be equipped with an "intelligent" car control which only
receives instructions for tasks to be carried out from the installation
control 11 on a higher command level and then plans and executes these on
its own.

[0041] However, the installation control 11 also receives messages, e.g.
status or error messages from the current sources 3' to 7', data on the
electrical states and values of the current sources 3' to 7', data on the
power, current and voltage conditions prevailing in the individual route
sections, when applicable data on the current operating states of the
cars F1 to F13, e.g. where a car is actually located at that moment,
which functions it is just executing, etc.

[0042] The transmission of the signals between the installation control
11, power control 5b and/or cars F1 to F13 can be carried out in a manner
known per se by cable, without contact by means of inductive coupling
between the suitably equipped route and cars F1 to F13 or even by
wireless communications means.

[0043] The installation control 11 also determines the total power
required at any moment in individual route sections, for which it uses
the current measurement of the current measuring device 5c and the
current measuring devices of the other route sections. In an alternative
embodiment the installation control 11 can also calculate the required
total power from the current and when applicable future operating states
of the cars F1 to F13 known to it so that current measurement can be
eliminated.

[0044] For example when the installation control 11 finds that no car F1
to F13 is present in a route section 3 to 7, it switches the route
section concerned to a voltageless and currentless state.

[0045] On the other hand, when the installation control 11 establishes
that one or more cars F1 to F13 are present in a route section, it
determines the required total power in this route section 3 to 7 on the
basis of the data known to it, i.e. of the cars F1 to F13 present there,
and then actuates the current source 3' to 7' concerned so that the
constant current fed in safely covers this total power. To avoid
continuous adjustment of the constant current, preferably a plurality of
supply levels can be defined between which the required total power of
the route section 3 to 7 concerned is determined depending on the total
power currently required by the cars F1 to F13 located there and
preferably also their future operating states, and then a corresponding
constant current is fed in. In the present case, four supply levels are
defined: supply level 1 corresponds to no power required, supply level 2
corresponds to a third and supply level 3 to half the maximum required
total power and thus the maximum constant current at full load. Supply
level 4 corresponds to the required total power or constant current at
full load. However, more or fewer supply levels can be defined as
required.

[0046] In FIG. 1 there is no car in the return journey section 7, so that
supply level 1 applies there, the return journey section 7 is voltageless
and currentless. In the second collecting section 4 it is only necessary
to supply the individual car controls of the cars F11 to F13, i.e. supply
level 2 with a third of the constant current IVL at full load is
sufficient. On the other hand, in the first collecting section 3 the car
controls of the four resting cars F7 to F10 and the travelling car F1 and
its propulsion drive must be supplied so that it is supplied at supply
level 3 with half the maximum constant current IVL. The same applies
to the outward journey section 5 in which the propulsion drive and car
control of the cars F5 and F6 must be supplied. In contrast, full load
operation applies in the working section 6 due to the operation of the
working units of the cars F3 and F4 and the propulsion drive of the cars
F2 and F3 so that there supply level 4 is set with the maximum constant
current at full load.

[0047] To allow the fastest possible adjustment of the supply levels to
changing conditions in the telpher system 1, the installation control 11
in particular uses the data known in advance to it or predetermined by
it. Thus, in FIG. 1 the installation control 11 uses the travel data of
the cars F2 to F4 to recognize that these will probably shortly travel
into the return journey section 7 (FIG. 2). It determines the expected
power requirement on the basis of the propulsion drives and car controls
of the cars F2 to F4 which have then to be supplied and therefore
transmits the corresponding signals to the current sources 7' to change
to supply level 2 in good time before the car F2 is driven in. This makes
it possible to ensure an uninterrupted power supply and thus travelling
of the car F2 and the cars F3 and F4 as well.

[0048] The same applies to the first collecting section 3, for there the
installation control 11 uses the control signals and operating data of
the car F1 known to it to determine that this will shortly reach its
resting position shown in FIG. 2 and that therefore it is possible to
switch from supply level 2 to supply level 1.

[0049] As the installation control 11 knows the cars F5 and F6 travelling
in the direction of the working section 6 in advance and knows from the
activities of the cars F5 and F6 planned there that the power requirement
there will still be large, it maintains supply level 4 there.

[0050] For a better understanding, the following table shows the power
requirement in the individual route sections in FIGS. 1 and 2 (VS: supply
level; IVL: current at full load):

[0051]FIG. 4 shows an example for the control process in the installation
control 11.

[0052] In state Z1 the telpher system 1 is in the resting state, the
individual route sections 3 to 7 are currentless and voltageless.
Interrogation stage Al continuously monitors whether a change occurs or
not. A change can be for example the start of operation of the telpher
system 1 after a standstill or an emergency stoppage. As long as no
change occurs, the telpher system 1 remains in the resting state. Now if
interrogation stage A1 reveals a change, for example a signal to start
operation from the installation control 11 or a higher level plant
control not shown, the system switches to the state Z2 and there the
required total power in the individual route sections 3 to 7 is
determined. This is done using the data on the individual cars F1 to F13
present in the installation control 11 and/or data transmitted from these
to the installation control 11.

[0053] In one advantageous embodiment, different operating states of the
individual cars F1 to F13 can be linked with different power values in
the installation control 11, e.g. in an assignment table, for faster
actuation. This then allows rapid comparison of the current operating
states of the individual cars F1 to F13 in a route section 3 to 7 with
the power already provided there to determine whether there is a need to
change this power.

[0054] In an alternative embodiment, when restarting from the resting
state Z1 every route section 3 to 7 can also be supplied with the maximum
constant current needed for operation at full load in order to ensure
that the telpher system 1 is set in operation reliably independently of
the current state of the individual route sections 3 to 7 and the cars F1
to F13. This can be expedient above all when restarting after an
emergency stoppage.

[0055] Then, the installation control 11 transmits the required total
power of the individual route sections 3 to 7 determined in the state Z2
to the associated current sources 3' to 7' for the adjustment (SQ in FIG.
4). Then, in interrogation stage A2 the installation control 11 checks
whether the desired state of provision of the energy supply has been
reached in the individual route sections 3 to 7.

[0056] If not, i.e. if the state of provision of the desired energy supply
is not confirmed by one or more of the current sources 3' to 7' in
interrogation stage A2, firstly the respective current source 3' to 7' is
checked for a fault in interrogation stage A3. If a fault is present,
then in state Z4 an error message is sent to the installation control 11
and this initiates a suitable measure. If no fault is present any longer
in interrogation stage A3, the system returns to state Z3 and the
required total power is transmitted again to the respective energy supply
devices 3' to 7', preferably only to the route sections 3 to 7 which are
not as yet ready in interrogation stage A2.

[0057] If the total power required in the route sections 3 to 7 is
available in interrogation stage A2, i.e. the corresponding constant
current is flowing in the primary conductor arrangement 2 of the route
sections 3 to 5, the cars F1 to F13 switch to the operating state Z5
predetermined by the installation control 11, as shown in FIG. 1.

[0058] The telpher system I is now in the normal state Z5, in which the
installation control 11 actuates the individual cars F1 to F13. The state
Z5 is monitored continually by the installation control 11 in
interrogation state A4. As long as no changes occur, the state Z5 is
maintained. If changes occur, for example the car F1 comes to its resting
position in FIG. 2, the installation control 11 in state Z2 determines
the required total power in the route sections 3 to 7 again. Then, in the
state Z3 it emits a corresponding message with the required total power
to the current sources 3' to 7' which then provide the required total
power as described above. Preferably the message with the changed
required total power is only sent in the affected route sections 3 to 7.
Thus, in the present embodiment example according to FIGS. 1 and 2 and
according to table 1, no message would be sent to the current sources 4'
and 6' in the state Z3 as there the required total power has not changed.